A simple module to measure the frequency of “normal” (simple) waveforms. The measurement supports zero-crossing (i.e. normal waves that run from -ve to +ve) as well as positive and negative polarity waves (measured at 2.5V and -2.5V respectively) and works well for low frequency waveforms and reasonably accurately (although there is some variation due to the internal sample rate) for simple audio waveforms.
Like the Dual Voltmeter, there is a selectable sample time (averaging the value over that time) which can be set OFF or between around 50ms and 1 second and there is a freeze button and trigger input. Due to the internal sample rate and the measurement approach, frequency measurement works up to around 21kHz.